The present invention relates to a structure of a plasma display panel (called hereinafter PDP) and more particularly, to a structure of a cell barrier of a color PDP and a method of manufacturing the same.
The conventional technology is first described with reference to FIGS. 11 and 12.
FIG. 11 shows one example representing a structure of a conventional DC-type PDP. Referring to FIG. 11, a flat front plate 121 and a flat rear plate 122 both made of a glass material are arranged parallel to each other in an opposing relation. Both of the plates are supported with a constant interval by cell barriers 123 arranged between the plates 121 and 122. A plurality of parallel anode elements 124 are formed on the rear surface of the front plate 121 and a plurality of parallel cathode elements 125 are also formed on the front surface of the rear plate 122 so as to extend in directions normal to the arrangement of the anode elements 124. A plurality of phosphor screens 126 are also formed on the rear surface of the front plate 121 adjacent both sides of the respective anode elements 124.
In the conventional DC-type PDP shown in FIG. 11, an electric field is produced by the application of a predetermined voltage between the anode elements 124 and the cathode elements 125, whereby an electric discharge is caused in the inside of a plurality of cells 127 as display elements each defined by the front and rear plates 121 and 122 and the cell barrier 123. Ultraviolet rays caused by this discharge make the phosphor screens 126 luminous and a light passing through the front plate 121 is visually observed by a viewer.
FIG. 12 also shows one example representing a structure of a conventional AC-type PDP. Referring to FIG. 12, a flat front plate 128 and a flat rear plate 129 both made of a glass material are arranged parallel to each other in an opposing relation. Both of the plates are supported with a constant interval by cell barriers 130 arranged between the plates 128 and 129. Two crossing electrodes 132 and 133 are disposed on the front surface of the rear plate 129 with a dielectric layer 131 interposed between the electrodes 132 and 133. A dielectric layer 134 and a protection layer 135 are further disposed on the front surface of the outer electrode 133. A phosphor screen 136 is formed on the rear surface of the front plate 128.
In the conventional AC-type PDP shown in FIG. 12, when an A.C. voltage is applied between the two electrodes 132 and 133, electric discharge is caused in a plurality of cells 137 each defined by the front and rear plates 128 and 129 and the cell barrier 130. Ultraviolet rays caused by this discharge make the phosphor screen 136 luminous and a light passing through the front plate 128 is visually observed by a viewer.
The phosphor screen of the conventional DC-type PDP or AC-type PDP of the structure described above is usually formed by coating a photosensitive slurry containing a phosphor, exposing the coated surface by utilizing a photomask having a structure corresponding to a pattern of the phosphor screen, and then carrying out developing and sintering operations. In the formation of a screen of a color PDP, these steps are carried out repeatedly with respect to the phosphor materials having red (R), green (G) and blue (B) colors, respectively. For example, a photosensitive slurry is formed of a mixture containing phosphor, polyvinyl alcohol (PVA) and diazonium salt, and in a certain case, an antifoaming agent and a interfacial active agent may be further added.
In the DC-type PDP and AC-type PDP of FIGS. 11 and 12, the light emitted from the phosphor screen passes through the phosphor screen and is visually observed by a viewer and a certain amount of light is reduced when it passes through the phosphor screen. In order to obviate such defect, there is also provided a PDP in which a phosphor screen is further formed on the wall surface of a cell barrier to increase the luminance and to visually observe a reflected light from the phosphor screen.
However, in the conventional structures of the PDP such as shown in FIGS. 11 and 12, in order to form the phosphor screens of the R, G and B colors on the wall surfaces of the cell barriers which had already been formed, the prior art provides a method for forming the phosphor screen by filling the phosphor coating material of the respective colors provided with the photosensitive properties in the cells, then exposing and developing the coated phosphor screen, or a method for forming the phosphor screen by spraying the respective colored phosphor coating materials one by one by spray method. However, these methods involve complicated processes or steps and provide the problem of the stable formation of the phosphor screen.